A variety of electronic communications systems, including electronic email (“email”) systems and instant messaging (IM) system are well known. In both email and IM systems, individual messages can be forwarded and replied to, and the content of a previous message can be copied and inserted into a new message and modified. However, for both email and IM, copying content and then modifying the content does not provide any way to quickly and efficiently view changes to the modified content. Furthermore, if multiple users have made changes to the content there is no mechanism for easily identifying which users made each of the changes to the content. Finally, such operations unnecessarily duplicate content that is common between successive versions of the content.